Sherlock uses his powers of deduction to consult on the murder of a young man who is shot upon entering his apartment. Meanwhile, Watson has dinner with her ex-boyfriend, Ty Morstan.

The relationships of four of the couples are tested – Will and Emma, Rachel and Finn, Kurt and Blaine, and Santana and Brittany but only one of them will survive.

In this flashback episode, return to the site of the plane crash and watch as each doctor tries to cope with the heartache and injuries caused by the crash. Meanwhile, back at Seattle Grace, everyone struggles to find a bit of normalcy amidst the chaos.

A Debate Highlight; Body Language; Depression Medication; Jim Lehrer: Tough Gig; What's New with Mitt; a Top Ten List; Funding Cut at PBS; a Simulation of Mitt Romney in the Guest Chair. TOP TEN PRESIDENT OBAMA EXCUSES - why such a poor performance Wednesday night? Craig has moved his "Late Late Show" into a new studio. The old one was small . . . small for a studio, but big for a closet. Anna is now starring in the new film, "Pitch Perfect" about competitive free-style acapella.

Dara O Briain and the regulars rifle through another week's events with guests Ed Byrne, Alun Cochrane and Gary Delaney.

Leslie helps a swim team get more practice time. Ron finds himself filling a pothole. April and Ben take a road trip to Pawnee.

As Reese investigates a cold case, he gets closer to Finch and his kidnapper, Root.

When a public figure is caught in a compromising position, Olivia and her team must do some heavy lifting, literally, in order to clean up the mess. But Olivia is still dealing with the ramifications of the judge's jaw-dropping verdict, and Abby continues to push for answers. In the White House, Cyrus and Fitz are forced to deal with a serious foreign policy emergency.

Sheldon tries to intervene when he learns that Penny is thinking about breaking up with Leonard; Howard is picked on.

Mitt Romney pledges to defund PBS, Chris Matthews berates Barack Obama, Pennsylvania rules against voter ID laws, and Harvard geneticist George Church explores DNA.

Actress Roseanne Barr; actress Keke Palme

Andy flaunts his genealogy when he discovers he's related to Michelle Obama. Meanwhile, Darryl struggles in his new post, Dwight teaches Erin a new language to wow her boyfriend's family, and Nellie tries to persuade Pam that Jim's having an affair.